I believe what you’re talking about I’ve screenshotted below:
View post on imgur.com
It definitely looks like it is generating a meta description at edit time. I also tried just pressing ‘update’ on the page thinking maybe it needed to be re-published, but no dice.
Yes, and when I edit the page I linked to in the original post I can see the plugin describing how the description will be displayed:
View post on imgur.com
And I can see the plugin generating its <head> elements on the page inside this comment block:
<!– All in One SEO 4.0.17 –>
metas etc here
<!– All in One SEO –>
But there is no <meta name=”description” in there (but it is there in more recent posts)